codejump
Academy

JavaScript

10 pages · about 54 min of reading

  1. 01Closures in JavaScriptWhat a closure is, why the variable outlives the function that created it, and the loop bug every JavaScript developer hits once.
  2. 02The JavaScript event loopHow one thread runs everything: the call stack, the microtask queue, timers, and why a promise always resolves before a setTimeout of 0.
  3. 03Promise.all, allSettled, race and anyThe four ways to combine promises, what each one does with a rejection, and how to pick the right one without guessing.
  4. 04How this is decided at call timeThe four rules that fix the value of this at call time, why extracting a method breaks it, and what arrow functions actually change.
  5. 05Prototypes and the prototype chainHow property lookup really works, what class is syntax for, and the difference between prototype and __proto__ that trips everyone up.
  6. 06Hoisting and the temporal dead zoneWhat is really moved to the top of a scope, why let and const are hoisted too, and the difference between undefined and a ReferenceError.
  7. 07Equality: ==, === and Object.isWhat loose equality really does, the two cases where === is not what you want, and why comparing objects almost never means what people expect.
  8. 08Shallow copy vs deep copyWhy spreading an object still shares its nested values, what structuredClone fixes, and what JSON round-tripping quietly destroys.
  9. 09Debounce vs throttleTwo ways to fire less often, and the one question that tells you which you need — do you want the last call, or a steady rate?
  10. 10Iterators and generatorsThe protocol behind for...of and spread, how a generator writes one for you, and why a paused function is the point.